Vocal Technologies Telephony Software
VOCAL Technologies continues to provide telephony software solutions to support legacy telecommunications systems even as these systems are supplanted by IP-based communications.
As the public telephone network evolved from simple analog to multiplexed analog carriers to digital carriers and optical carriers, many new conventions and standards were added. And as is typical in this field, very few standards have been successfully deprecated and eradicated. In today’s systems, even though IP-based communications is now the de facto implementation, support of the legacy telecommunications standards is essential.
Low Speed Digital Carrier Systems (DS1) – Multiplexed voice/data carried over twisted pair copper wires.
- T1 – 1.544 Mbps used in North America
- J1 – 1.544 Mbps used in Japan
- E1 – 2.048 Mbps used world-wide
High Speed Digital Carrier Systems (DS3/4) – Multiple DS1 carriers delivered over fiber optic (SONET) links with local coax cable connections.
- T3 – 44.736 Mbps used in North America, carries 28 T1’s
- E3 – 34.368 Mbps used world-wide, carries 16 E1’s
- E4 – 139.264 Mbps used world-wide, carries 64 E1’s
Analog Systems (DS0) – Analog circuits/termination found at each end of a twisted pair copper wires.
- FXS – Foreign Exchange Station
- FXO – Foreign Exchange Office
Terminal Devices – Analog or digital circuits used to support a human-machine interface (HMI) or machine to machine interface (MMI).
- Speakerphone – telephone with optional LCD display
- Feature Phone – speakerphone with features/keys and a LCD display
- Modem – standalone data or facsimile modem or built into terminal devices
- Media Gateway – conversion device to intermix VoIP and legacy PSTN voice technologies
- Analog Telephone Recorder – call recording device for legacy PSTN voice technologies
